Traffic lights provide guidance to motorists approaching an intersection, on-ramp, railroad crossing, etc. by indicating to the motorist whether to pass through the intersection or stop. Motorists must obey traffic lights by law, and traffic lights are thereby useful in coordinating the flow of traffic through an intersection. Typically, a traffic light provides a green light to instruct motorists to continue through the intersection and provides a yellow light, which follows the green light, to instruct motorists to begin slowing to a stop. A red light, which follows the yellow light and precedes the green light, instructs motorist to remain stopped and not pass through the intersection. Because the traffic light can change phases at any time, motorists must repeatedly focus their attention on the traffic light when approaching and passing through an intersection.
A traffic light creates an opportunity to provide additional information to motorists because the motorists must focus their attention toward the traffic light. This is especially true during red lights when the motorist has stopped the vehicle and may focus continuously on the traffic light in anticipation of a change to a green light. To capitalize on this opportunity, it has been proposed that a programmable sign display may be located in proximity to the traffic light, such as on the same pole, so that motorists see the programmable sign display when directing attention toward the traffic light. Various uses of the programmable sign display have been proposed, such as providing advertising or providing an indication that an emergency vehicle is approaching. However, a failure to further develop or refine systems that involve the programmable display sign may have resulted in a lack of commercial acceptance.